Magnetic flux leakage internal detection system for gas pipe network detection and control method

Abstract

The invention discloses a magnetic flux leakage internal detection system for gas pipe network detection and a control method, and mainly relates to the technical field of gas pipeline internal detection. Comprising a main power section, a magnetic leakage section, an auxiliary power section and a universal joint, the main power section comprises a power section sealing cabin, the power section sealing cabin is of a hollow cylindrical structure, an odometer wheel module is arranged on the outer side wall of the main power section sealing cabin, and a control circuit support and a battery control support are arranged in the main power section; the two ends of the main power section are provided with an end cover for debugging and a rear end cover respectively, the rear end cover and the magnetic leakage section are connected through a universal joint, and the magnetic leakage section and the auxiliary power section are connected through a universal joint. The device has the beneficial effects that the walking friction resistance of the magnetic flux leakage inner detector is reduced, and the bidirectional movement in a pipe network is also realized.

Description

Technical Field

[0001] The present invention relates to the technical field of in-line inspection of gas pipelines, and particularly to a magnetic flux leakage in-line inspection system and a control method for gas pipeline network inspection. Background Art

[0002] Due to problems such as low pressure, unstable flow rate, many small-bore elbows, no pig launcher and receiver, frequent changes in pipe diameter, large bending degree, and non-standard construction and renovation in urban gas pipelines, traditional one-way in-line detectors often cannot smoothly pass through all pipe sections, greatly increasing the risk of pig getting stuck. In addition, since the power source of the in-line detector depends on the pressure difference generated by the front and rear media during its movement in the pipeline, restricted by the low gas pressure and flow rate in urban gas pipelines, an in-line detector with a low friction design can significantly reduce the risk of pig getting stuck.

[0003] Existing in-line detectors have the following defects:

[0004] 1. Using a steel brush as the magnetic conduction structure, which is in direct contact with the pipe wall, has a large friction force and a large running resistance;

[0005] 2. The elbow radius of long-distance oil and gas pipelines is greater than 5D, so elbows below 5D are not considered in the design of in-line detectors;

[0006] 3. The butterfly leather cups used in in-line detectors for long-distance oil and gas pipelines cannot move bidirectionally, only unidirectionally, and mechanical components such as odometers, support wheels, and probes that contact the pipe wall cannot move bidirectionally due to structural reasons.

[0007] Compared with long-distance pipelines, urban gas pipelines are often more complex and diverse, with frequent changes in pipe diameter, greater bending degree, and more non-standard construction and renovation situations, resulting in higher application difficulty of traditional in-line detectors in these environments. The above defects often lead to the following problems and disadvantages:

[0008] 1. Large running resistance: Urban gas pipelines have low pressure and unstable flow rate, and cannot provide enough driving force for the in-line detector;

[0009] 2. Unable to pass through small-bore elbows: Urban gas pipelines are complex, with a large number of small-bore elbows such as 1.5D and 3D;

[0010] 3. Unable to move bidirectionally: Most urban gas pipelines have no pig launcher and receiver, and a temporary pig launcher and receiver need to be installed. When the in-line detector encounters pipeline structures such as reduced diameter and valves that cannot be passed through, it needs to be pushed back into the pig launcher in the reverse direction.

[0011] Therefore, there is an urgent need for a bidirectional, low-friction magnetic flux leakage in-line detector for urban gas pipeline network inspection and its control method to solve the above problems. Summary of the Invention

[0012] The object of the present invention is to provide a magnetic flux leakage internal detection system and a control method for gas pipeline network detection, which can reduce the running friction resistance of the magnetic flux leakage internal detector and realize bidirectional movement in the pipeline network.

[0013] To achieve the above object, the present invention is realized through the following technical solutions:

[0014] On the one hand, a magnetic flux leakage internal detection system for gas pipeline network detection is provided, including a main power section, a magnetic flux leakage section, a secondary power section and a universal joint. The main power section includes a power section sealing cabin, which is a hollow cylindrical structure. A mileage wheel module is arranged on the outer side wall of the power section sealing cabin. A control circuit bracket and a battery control bracket are arranged inside the main power section. Debugging end caps and rear end caps are respectively arranged at both ends of the main power section. The rear end cap is connected to the magnetic flux leakage section, and the magnetic flux leakage section is connected to the secondary power section through a universal joint.

[0015] Preferably, a sealing straight leather cup module is connected to one end of the power section sealing cabin close to the debugging end cap. A fixed baffle is connected to the side of the sealing straight leather cup module away from the power section sealing cabin. An anti-collision ring is connected to the side of the fixed baffle away from the power section sealing cabin. The anti-collision ring is a circular ring structure, and the trial end cap is arranged inside the anti-collision ring.

[0016] Preferably, the mileage wheel module includes two fixed blocks. A mileage main spring is arranged on the top surfaces of the two fixed blocks. The two ends of the mileage main spring are respectively connected to the fixed blocks. A mileage support platform is arranged on the top surface at the middle position of the mileage main spring. A mileage wheel is arranged on the bottom surface at the middle position of the mileage main spring. A mileage wheel support spring is arranged below the mileage wheel.

[0017] Preferably, the universal joint includes a steel chain. A first fixed pin shaft and a second fixed pin shaft are respectively arranged at both ends of the steel chain. Connecting joints are connected to the ends of the first fixed pin shaft and the second fixed pin shaft away from the steel chain.

[0018] Preferably, the magnetic flux leakage section includes two support leather cups. A magnetic circuit module is arranged between the two support leather cups. Both support leather cups are hollow circular gear-shaped structures. A connecting end cap is arranged at the center position of the two support leather cups. A number of magnetic circuit modules are arranged and are circumferentially arrayed along the circumferential side of the support leather cup.

[0019] Preferably, the magnetic circuit module includes a support body, magnetic circuit support fixing seats are respectively arranged at two ends of the support body, a magnetic circuit support spring is arranged inside the two magnetic circuit support fixing seats, two ends of the magnetic circuit support spring are respectively arranged on the top surface of the support body, support arms are respectively arranged on the two magnetic circuit support fixing seats, armatures are arranged at one ends of the two support arms away from the magnetic circuit support fixing seats, support wheels and magnet modules are respectively arranged at two ends of the top surface of the armature, and a sensor module is arranged in the middle of the two magnet modules.

[0020] Preferably, the two magnet modules include magnet support seats, permanent magnets are arranged on the top surfaces of the magnet support seats, stainless steel spacers are arranged on the top surfaces of the permanent magnets, and wear-resistant blocks are arranged on the top surfaces of the stainless steel spacers.

[0021] Preferably, the sensor module includes a polyurethane base, the polyurethane base is a cuboid plate-like structure, a fixing plate is arranged on the top surface of the polyurethane base, connecting rods are respectively arranged at four vertex positions of the polyurethane base, a probe box is arranged between the two connecting rods on the long side of the polyurethane base, and wear-resistant ceramics are arranged on the top surface of the probe box.

[0022] On the other hand, a control method applied to the above-mentioned magnetic flux leakage internal detection system for gas pipeline network detection is provided, including the following steps:

[0023] S1: Collect the data information of the mileage module, and preprocess the collected data;

[0024] S2: Calibrate the data after preprocessing;

[0025] S3: Fuse the processed data of the mileage module.

[0026] Preferably, the step S1 is specifically: collect the sensor data in each module, perform smoothing processing on the data of each sensor, use moving average or low-pass filtering to reduce the random fluctuations in the signal, and set a threshold in the sensor to detect in real time whether the data of a single sensor deviates greatly. If the sensor data is significantly abnormal, it is excluded;

[0027] The step S2 is specifically: adjust its weight in the fusion according to the debugging, pulling data or historical monitoring data, and assign a high weight to the sensor with high accuracy;

[0028] The step S3 is specifically: after preprocessing and calibrating the sensor data, synthesize the data of the sensors into the mileage data of a module through weighted average.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1. By adopting mechanisms such as supporting wheels that are beneficial for walking, direct contact between the internal detector and the pipe wall is prevented, the friction of the internal detector walking in the pipe network is reduced, thereby reducing the running resistance of the internal detector and lowering the risk of blockage of the internal detector.

[0031] 2. By adding a universal joint, the passability of pipe networks with different diameters is increased.

[0032] 3. Bidirectional walking of the internal detector in the pipe network is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is the front view of the overall structure of the present invention;

[0034] Figure 2 is the schematic structural diagram of the main power section of the present invention;

[0035] Figure 3 is the schematic structural diagram of the mileage module of the present invention;

[0036] Figure 4 is the schematic internal structure diagram of the main power section of the present invention;

[0037] Figure 5 is the schematic structural diagram of the universal joint of the present invention;

[0038] Figure 6 is the schematic structural diagram of the magnetic flux leakage section of the present invention;

[0039] Figure 7 is the schematic structural diagram of the magnetic circuit module of the present invention;

[0040] Figure 8 is the schematic structural diagram of the sensor module of the present invention;

[0041] Figure 9 is the data acquisition flow chart of the three-axis magnetic flux leakage digital sensor of the present invention;

[0042] Figure 10 is the circuit structure diagram of the eddy current sensor coil receiver of the present invention;

[0043] Figure 11 is the schematic structural diagram of the data acquisition and storage of the present invention;

[0044] Figure 12 is the schematic structural diagram of the auxiliary power section of the present invention;

[0045] Figure 13 is the data acquisition logic flow chart of the main drive section of the present invention;

[0046] Figure 14 is the schematic block diagram of the sensor circuit principle of the present invention

[0047] Figure 15 Schematic diagram of the connection mode between the sensor circuit and the junction box circuit of the present invention

[0048] Figure 16 Flowchart of the control method of the present invention

[0049] Reference numerals shown in the accompanying drawings:

[0050] 1. Main power section; 2. Magnetic flux leakage section; 3. Universal joint; 4. Sub-power section; 101. Power section sealing cabin; 102. Odometer wheel module; 103. Straight leather cup; 104. Support leather cup; 105. Anti-collision ring; 106. End cover for debugging; 107. Fixed baffle; 108. Rear end cover of the main power section; 1021. Odometer support platform; 1022. Odometer wheel; 1023. Main spring of the odometer wheel; 1024. Support spring of the odometer wheel; 1025. Fixed stop block; 1081. First wire harness; 1082. Control circuit; 1083. Battery box; 1084. Debugging interface; 301. Steel chain; 302. First fixed pin shaft; 303. Second fixed pin shaft; 304. Connection end; 201. Magnetic circuit module; 202. Connection end cover; 2021. Support main body; 2022. Magnetic circuit support fixing seat; 2023. Magnetic circuit support spring; 2024. Support arm; 2025. Armature; 2026. Magnet support seat; 2027. Permanent magnet; 2028. Stainless steel spacer; 2029. Sensor module; 20210. Wear-resistant block; 20211. Support wheel; 20291. Polyurethane base; 20292. Fixed plate; 20293. Probe box; 20294. Wear-resistant ceramic Detailed implementation manners

[0051] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by this application

[0052] In the present invention, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings. They are only relationship terms determined for the convenience of describing the structural relationship of each component or element of the present invention, and do not specifically refer to any component or element of the present invention, and should not be construed as a limitation of the present invention

[0053] In the present invention, terms such as "fixed connection", "connected", "joined" and the like should be understood in a broad sense, which may mean a fixed connection, an integral connection or a detachable connection; it may be directly connected or indirectly connected through an intermediate medium. For relevant scientific research or technical personnel in this field, the specific meanings of the above terms in the present invention can be determined according to specific circumstances, and should not be construed as a limitation to the present invention.

[0054] Embodiment:

[0055] As Figure 1 shown, this embodiment provides a magnetic flux leakage internal detection system for gas pipeline network detection. The cast iron mechanism includes a main power section, a magnetic flux leakage section, a sub-power section and a universal joint. The main power section includes a power section sealed cabin, which is a hollow cylindrical structure. A mileage wheel module is arranged on the outer side wall of the main power section sealed cabin. A control circuit bracket and a battery control bracket are arranged in the main power section. A debugging end cover and a rear end cover are respectively arranged at both ends of the main power section. The rear end cover and the magnetic flux leakage section, and between the magnetic flux leakage section and the sub-power section are both connected through a universal joint.

[0056] In this embodiment, the internal detection system includes one main power section, one sub-power section, two magnetic flux leakage sections and three universal joints. The main power section and the sub-power section are basically the same in appearance, but 3 groups of mileage wheel modules are installed on the main power section. In this embodiment, a battery is arranged in the main power section, and a data processing circuit, a storage circuit, etc. and / or an IMU are arranged in the sub-power section. In the actual application of this embodiment, the main and sub-power sections are mainly considered for the running direction and can be interchanged. In addition, the magnetic circuits of the magnetic flux leakage sections in this embodiment are arranged in a cross pattern to facilitate the probe to achieve full coverage of the pipe diameter.

[0057] As Figure 2 shown, the main power section is composed of a power section sealed bin, a fixed baffle, an anti-collision ring, a sealed straight leather bowl, and a mileage wheel module. The sealed straight leather bowl includes: a support leather bowl and a straight leather bowl;

[0058] Wherein, ring structures are integrally arranged at both ends of the power section sealed cabin. The perimeter of the ring structure is greater than the perimeter of the side surface of the power section sealed cabin. A straight leather cup, a support leather cup, a fixed baffle, and an anti-collision ring are successively arranged at one end close to the debugging end cover. Both the straight leather cup and the fixed baffle are circular ring structures. The support leather cup is a circular ring structure with a diameter slightly smaller than that of the straight leather cup, and gear teeth are arranged in a circumferential array on the circumferential side of the support leather cup. The ring structure, the support leather cup, the straight leather cup, and the fixed baffle are all coaxial and concentric with the power section sealed cabin, and a number of screw holes are arranged on the surfaces of the ring structure, the support leather cup, the straight leather cup, and the fixed baffle. The screw holes are all coaxial and of the same diameter, and are fitted with bolts. Through the bolts, the support leather cup, the straight leather cup, and the fixed baffle can be fixed to one end of the power section sealed cabin. An anti-collision ring is fixed on the outer side of the support leather cup. The debugging end cover is arranged inside the straight leather cup, the support leather cup, the fixed baffle, and the anti-collision ring, and is hermetically connected to the power section sealed cabin.

[0059] The sealed straight leather cup plays a sealing role and provides the driving force for the detector to move forward by the pressure difference between the front and rear media. The interference fit is set to 1%-5% of the inner diameter of the pipeline.

[0060] The anti-collision ring plays an anti-collision role and is made of materials such as nylon material / polyurethane.

[0061] The support leather cup can not only avoid eccentricity but also play a good supporting role for the sealed straight leather cup.

[0062] As Figure 3 shown, in this embodiment, the mileage wheel module includes two fixed blocks. The two fixed blocks are respectively fixedly connected to the ring structures at both ends of the power section sealed cabin. A mileage main spring is arranged on the top surfaces of the two fixed blocks. The mileage main spring is arranged in a trapezoidal state. The two ends of the mileage main spring are respectively connected to the fixed blocks. A mileage support platform is arranged on the top surface at the middle position of the mileage main spring. A mileage wheel is arranged on the bottom surface at the middle position of the mileage main spring. There are four mileage wheels and they are grouped in pairs. The center positions of each group of mileage wheels are connected by bearings. The two groups of mileage wheels are linearly arrayed along the length direction of the mileage support platform. A mileage wheel support spring is arranged on the lower side of the mileage wheel. The mileage wheel support spring is also arranged in a trapezoidal state. The two ends of the mileage wheel support spring are fixed on the power section sealed cabin, and the included angle between the two ends of the mileage wheel support spring and the power section sealed cabin is greater than the included angle between the two ends of the mileage main spring and the power section sealed cabin.

[0063] The mileage main spring and the mileage support spring act together to ensure that the mileage wheel is in close contact with the wall of the pipeline to be measured, and can have sufficient elasticity and toughness when encountering features such as welds, elbows, and tees.

[0064] The encoder adopted in the mileage wheel is AS5045B. The encoder is placed in the hollow mileage support platform and is provided with an electronic circuit.

[0065] As Figure 4 shown, the control circuit bracket is fixed to the rear end cover of the power section with screws, and the control circuit bracket is fixed to the battery control bracket with screws. There are mounting holes for the electronic package (including data analysis circuit, power control circuit, etc.) inside the control circuit bracket, and fixing holes for the battery inside the battery control bracket. The battery supplies power to sensors such as the electronic package, odometer wheel, composite sensor, acceleration sensor, pressure sensor, and temperature sensor. There is a certain notch on the rear end cover of the power section to facilitate the routing of the odometer wheel's wire;

[0066] There is a debugging interface at the front end of the battery control bracket. After opening the debugging end cover, the debugging line can be directly inserted into the debugging interface and connected to the debugging computer for device debugging. It can also download the detected data. This debugging interface is connected to the electronic package.

[0067] As Figure 5 shown, in this embodiment, the universal joint includes a steel chain. The two ends of the steel chain are respectively provided with a first fixed pin shaft and a second fixed pin shaft. The ends of the first fixed pin shaft and the second fixed pin shaft away from the steel chain are connected with connection joints. The outside of the steel chain inside the universal joint is wrapped with polyurethane, which has both bendability and can withstand a certain circumferential thrust, facilitating the pushing of the device during serving. The steel chain uses 40Cr material. The universal joint is connected to the rear end cover of the main power section and the front end cover of the magnetic leakage section, and at the same time, the universal joint is also connected to the rear end cover of the magnetic leakage section and the front end cover of the auxiliary power section.

[0068] As Figure 6 shown, the magnetic leakage section includes two support leather cups. A magnetic circuit module is arranged between the two support leather cups. A connection end cover is arranged at the center position of the two support leather cups. There are several magnetic circuit modules, and they are arranged in a circular array along the circumferential side of the support leather cup.

[0069] As Figure 7 shown, the magnetic circuit module includes a support body. The two ends of the support body are respectively provided with magnetic circuit support fixing seats. A magnetic circuit support spring is arranged inside the two magnetic circuit support fixing seats. The two ends of the magnetic circuit support spring are respectively arranged on the top surface of the support body. Support arms are respectively arranged on the two magnetic circuit support fixing seats. Armatures are arranged at the ends of the two support arms away from the magnetic circuit support fixing seats. Support wheels and magnet modules are respectively arranged at the two ends of the top surface of the armature. A sensor module is arranged between the two magnet modules. The two magnet modules include magnet support seats. Permanent magnets are arranged on the top surfaces of the magnet support seats. Stainless steel spacers are arranged on the top surfaces of the permanent magnets. Wear-resistant blocks are arranged on the top surfaces of the stainless steel spacers.

[0070] The wear-resistant sheet uses 65Mn, and the part in contact with the pipeline adopts a local quenching process with a quenching depth ≥ 3mm. There are protrusions at both ends of the wear-resistant sheet, which can hook the permanent magnet to prevent the problem of the wear-resistant sheet shifting due to impact in the pipeline;

[0071] All support arms of the magnetic circuit are made of 2205 duplex stainless steel, which has high strength, good impact toughness, and good overall and local stress corrosion resistance. The yield strength is ≥450 MPa, which is more than twice that of ordinary austenitic stainless steel, playing a role in reducing weight.

[0072] The support wheel structure is arranged before and after the magnetic circuit, converting the axial force during bidirectional walking into a part of the radial force, enabling the magnetic circuit structure to deform. The magnetic circuit support arm is a symmetric structure, and there are waist-shaped holes at the connection position with the fixed seat shaft, which can change the length of the support arm. When encountering pipe wall deformation, the height of the magnetic circuit can be reduced. The magnetic circuit is supported by magnetic circuit support springs below, and the two support points in contact with the skeleton are floating structures, allowing the magnetic circuit to move back and forth during movement.

[0073] The main functions of the front and rear support wheels of the magnetic circuit are:

[0074] 1. Fix the distance between the magnetic circuit and the pipe wall, creating a certain gap between the magnetic circuit and the pipe wall to reduce the frictional resistance of the magnetic circuit in the pipeline.

[0075] 2. When encountering raised parts such as changes in pipe wall thickness, misalignment, and welds during operation, the contact of the roller structure can generate a certain radial force, causing the magnetic circuit structure to descend.

[0076] The support wheels used in this embodiment are made of stainless steel.

[0077] The magnet module consists of an iron core (armature), a permanent magnet, and a wear-resistant sheet. Among them, the iron core and the permanent magnet form a permanent magnet magnetization unit module. The permanent magnet is installed in the magnetic box, and the four sides of the magnetic box are firmly welded by laser, which can effectively avoid the permanent magnet from being stressed, and at the same time prevent the permanent magnet from rusting and being damaged. The magnetic box is provided with fixing holes and installation process holes for convenient installation. The permanent magnet materials used in this embodiment are neodymium iron boron permanent magnets such as N48H and N52H, and the iron core (armature) material is Q235.

[0078] As Figure 8 shown, the sensor module includes a polyurethane base, which is a rectangular plate-like structure. A fixing plate is arranged on the top surface of the polyurethane base. Connecting rods are respectively arranged at the four vertex positions of the polyurethane base. A probe box is arranged between the two connecting rods on the long side of the polyurethane base. A wear-resistant ceramic is arranged on the top surface of the probe box.

[0079] Among them, the probe box is made of PEEK material. The wear-resistant ceramic, the probe box, and the sensor circuit are finally formed by epoxy resin casting, ensuring compression resistance while increasing wear resistance. The probe box is connected to the polyurethane base by fixing rivets, and the fixing plate plays a role in fixing the polyurethane base on the armature.

[0080] This structure is a bidirectional symmetric support. When walking inside the pipeline, no matter in which direction, it can ensure the consistency of the probe attitude, ensure that the probe can always be close to the inner wall of the pipeline, and ensure the quality of data acquisition.

[0081] The composite electromagnetic probe is installed and arranged in the center of the magnetic circuit through a polyurethane flexible base. Each group of probes includes 6 triaxial magnetic flux leakage sensors and two differential PCB printed eddy current sensors, which pick up the magnetic flux leakage signal and eddy current impedance transformation signal of the pipeline in real time at a frequency of 2.5K. The eddy current sensor cannot pick up the defects outside the pipe wall and can only pick up the defects on the inner wall of the pipeline. The magnetic flux leakage sensor is sensitive to both inner and outer wall defects of the pipe wall. By discriminating the defect identification of the magnetic flux leakage and eddy current sensors, the inner and outer wall arrangements of the pipe wall defects are distinguished. The above-mentioned collected signals are output through the protocol conversion chip in SPI protocol. The composite probe cable is collected and processed through the wire junction box and connected to the electronic package. The composite probe and the wire junction box are connected by connectors, and each probe can be replaced separately.

[0082] The triaxial magnetic flux leakage digital sensor is transmitted to the ARM-STM32 control probe system through the IIC communication protocol. The eddy current coil is excited by the control system, and the detected signal is received through the eddy current coil receiving circuit and transmitted to the ARM-STM32 control probe system through the SPI protocol. The system includes a high-precision clock module, a regulated power supply module, a storage module, a bus protocol module, and a FATFS file management module to collect and store the sensor data, and transmits the data to the data acquisition system through the data output driver. Its transmission logic is as Figure 9 shown.

[0083] The triaxial magnetic flux leakage digital sensor selects low-power magnetic sensors such as MLX90393. After the eddy current coil is excited, the signal generated by the eddy current coil is received through the eddy current sensor coil receiving circuit. The receiving circuit diagram is as Figure 10 shown.

[0084] Both ends of the coil are connected to the INA and INB signal terminals respectively. During the circuit processing, the LC oscillation excitation circuit provides the excitation voltage, excitation frequency and other parameters for the eddy current sensor coil. When the eddy current sensor coil detects the defect on the inner wall of the pipe wall, the impedance changes. The inductance value is detected by the inductance value measurement circuit, processed by the register and the logic processor, and then compared with the threshold value, and converted into an SPI communication protocol output signal to judge the defect condition of the pipe wall;

[0085] The CSB, SCLK, SDI, and SDO signals output by the SPI communication protocol are transmitted through transmission lines to the single-chip microcomputer acquisition system. The main control of the single-chip microcomputer selects the ARM-STM32 series of chips. Among them, CLKIN represents the external time-base clock input, and a 15nF capacitor is externally connected from the pin to GND. CSB means that multiple channels can be connected to the same SPI bus. SCLK represents the SPI communication protocol clock input. SDI represents the SPI data input connected to the MOSI of the SPI host. SDO represents the SPI data output connected to the MISO of the SPI main control. The data acquisition and storage structure is as Figure 11 shown.

[0086] As Figure 12 shown, in this embodiment, the secondary power section is basically similar to the primary power section in terms of structure and is in a symmetrical state, but it is different in terms of the power circuit. The leakage magnetic and eddy current signal acquisition circuits are not designed in the secondary power section. (The installation positions of other components can be reserved, such as for the IMU, backup battery, and low-frequency transmitter)

[0087] As Figure 13 shown, it is the data acquisition logic of the primary power section. The data acquisition and storage system uses an ARM transplanted with Linux as the control core, an FPGA as the data acquisition interface, a TF card as the storage medium, a USB as the data output interface, and an Ethernet as the communication interface with the upper computer to complete the functions of data acquisition, storage, and transmission of a large number of digital signals;

[0088] The FPGA is mainly responsible for data acquisition and data transmission. The ARM is mainly responsible for data reception, data storage, data upload, and communication with the upper computer. Through the instantiated multi-channel SPI and I2C interfaces, the FPGA can collect the probe sensor and peripheral data in real time, cache it in the SDRAM in a certain data format, and then transfer the data to the ARM through the USB FIFO. The ARM then stores the acquired data in the TF card group according to a certain file name and format through the FatFS file system. The serial port is used for programming and debugging. The USB3.0 can be used not only to download and transplant the Linux system but also to mount the TF to the PC side in the upload mode for high-speed data upload. The network port is used to connect to the upper computer software in the debugging mode and can display the status of the probe sensor and peripherals in real time.

[0089] Among them, the FIFO-to-USB chip selects the FT232H and uses a serial EEPROM interface. This device can be configured into various asynchronous and synchronous serial standards, and the I / O structure is 3.3V, which has greater flexibility when interfacing with the FPGA;

[0090] AX88179 is used to connect the ARM and the host computer software. During debugging, it can transmit the commands from the host computer software to the ARM to set the system, and can also transmit the data received by the ARM to the host computer for analysis, so as to understand the status of the probe sensor and peripherals in real time;

[0091] FE8.1 integrates the data of the downstream network port to USB circuit and the FIFO to USB circuit and exchanges data with the upstream ARM;

[0092] The HD3SS6126 device is a high-speed passive switch designed for USB applications, used to route the ultra-high-speed USB RX and TX and USB 2.0 DP and DM signals from the source location to the target location, and vice versa;

[0093] During data acquisition, the ARM switches to the storage module through SEL and stores the data in the TF card; during data upload, it switches to USB3.0, mounts the TF card to the computer, and the stored data can be copied out for analysis.

[0094] The sensor circuit realizes the acquisition and transmission of magnetic flux leakage signals and eddy current signals, and is composed of a Hall sensor group, an eddy current excitation and receiving coil, an A / D conversion circuit and a single-ended differential conversion, as Figure 14 shown;

[0095] In order to make the structure of the whole detector more compact, reduce the number of incoming wires in the electronic compartment, a wire junction box is added as a transition between the sensor and the data acquisition and storage system, as Figure 15 shown.

[0096] In addition, as Figure 16 shown, this embodiment also provides a control method for a magnetic flux leakage internal detection system for gas pipeline network detection, which is applied to the control of the odometer wheel module, and includes the following steps:

[0097] S1: Collect the data information of the odometer module and preprocess the collected data;

[0098] S2: Calibrate the preprocessed data;

[0099] S3: Fuse the processed data of the odometer module.

[0100] Step S1 is specifically: collect the sensor data in each module, smooth the data of each sensor, use moving average or low-pass filtering to reduce the random fluctuations in the signal, and set a threshold in the sensor to detect in real time whether the data of a single sensor deviates greatly. If the sensor data is significantly abnormal, it will be excluded;

[0101] Step S2 is specifically as follows: According to the debugging, pulling data or historical monitoring data, adjust its weight in the fusion, and assign a high weight to the sensor with high accuracy;

[0102] Step S3 is specifically as follows: After preprocessing and calibrating the sensor data, synthesize the sensor data into the mileage data of a module by weighted average.

[0103] The above is a specific description of the preferred embodiment of the present invention, but the present invention is not limited to the described embodiment. Those skilled in the art can also make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A magnetic flux leakage internal detection system for gas pipeline network detection, characterized in that, It includes a main power section, a magnetic flux leakage section, a sub-power section and a universal joint. The main power section includes a power section sealed cabin, which is a hollow cylindrical structure. A mileage wheel module is arranged on the outer side wall of the power section sealed cabin. A control circuit bracket and a battery control bracket are arranged inside the main power section. Debugging end caps and rear end caps are respectively arranged at both ends of the main power section. The rear end cap and the magnetic flux leakage section, and the magnetic flux leakage section and the sub-power section are connected by universal joints.

2. The magnetic flux leakage internal detection system for gas pipeline network detection according to claim 1, wherein One end of the power section sealed cabin close to the debugging end cap is connected with a sealed straight leather cup module. One side of the sealed straight leather cup module away from the power section sealed cabin is connected with a fixed baffle. One side of the fixed baffle away from the power section sealed cabin is connected with an anti-collision ring. The anti-collision ring is a circular structure. The trial end cap is arranged inside the anti-collision ring.

3. The magnetic flux leakage internal detection system for gas pipeline network detection according to claim 1, wherein The mileage wheel module includes two fixed blocks. A mileage main spring is arranged on the top surfaces of the two fixed blocks. Both ends of the mileage main spring are respectively connected with the fixed blocks. A mileage support platform is arranged on the top surface at the middle position of the mileage main spring. A mileage wheel is arranged on the bottom surface at the middle position of the mileage main spring. A mileage wheel support spring is arranged below the mileage wheel.

4. The magnetic flux leakage internal detection system for gas pipeline network detection according to claim 1, characterized in that The universal joint includes a steel chain. A first fixed pin shaft and a second fixed pin shaft are respectively arranged at both ends of the steel chain. Connecting joints are connected to the ends of the first fixed pin shaft and the second fixed pin shaft away from the steel chain.

5. The magnetic flux leakage internal detection system for gas pipeline network detection according to claim 1, characterized in that, The magnetic flux leakage section includes two support leather cups. A magnetic circuit module is arranged between the two support leather cups. Both support leather cups are hollow circular gear-shaped structures. A connecting end cap is arranged at the center positions of the two support leather cups. A number of magnetic circuit modules are arranged and are circumferentially arrayed along the circumferences of the support leather cups.

6. The magnetic flux leakage internal detection system for gas pipeline network detection according to claim 5, wherein The magnetic circuit module includes a support body. Magnetic circuit support fixed seats are respectively arranged at both ends of the support body. A magnetic circuit support spring is arranged inside the two magnetic circuit support fixed seats. Both ends of the magnetic circuit support spring are respectively arranged on the top surface of the support body. Support arms are respectively arranged on the two magnetic circuit support fixed seats. Armatures are arranged at the ends of the two support arms away from the magnetic circuit support fixed seats. Support wheels and magnet modules are respectively arranged at both ends of the top surface of the armature. A sensor module is arranged between the two magnet modules.

7. The magnetic flux leakage internal detection system for gas pipeline network detection according to claim 6, characterized in that The two magnet modules include magnet support seats. Permanent magnets are arranged on the top surfaces of the magnet support seats. Stainless steel spacers are arranged on the top surfaces of the permanent magnets. Wear-resistant blocks are arranged on the top surfaces of the stainless steel spacers.

8. The magnetic flux leakage internal detection system for gas pipeline network detection according to claim 6, characterized in that, The sensor module includes a polyurethane base, which is a rectangular plate-like structure. A fixing plate is arranged on the top surface of the polyurethane base. Connecting rods are respectively arranged at the four vertex positions of the polyurethane base. A probe box is arranged between the two connecting rods on the long side of the polyurethane base. Wear-resistant ceramics are arranged on the top surface of the probe box.

9. A control method applied to the magnetic flux leakage internal detection system for gas pipeline network detection as described in claim 1, characterized in that, It includes the following steps: S1: Collect the data information of the mileage module and preprocess the collected data; S2: Calibrate the data after preprocessing; S3: Fuse the processed data of the mileage module.

10. A control method according to claim 9, characterized in that, The specific steps of step S1 are as follows: Collect the sensor data in each module, perform smoothing processing on the data of each sensor, using moving average or low-pass filtering to reduce the random fluctuations in the signal, and set a threshold in the sensor to detect in real time whether the data of a single sensor deviates greatly. If the sensor data is significantly abnormal, it will be excluded; The specific steps of step S2 are as follows: Adjust its weight in the fusion according to the debugging, pulling data or historical monitoring data, and assign a high weight to the sensor with high accuracy; The specific steps of step S3 are as follows: After preprocessing and calibrating the sensor data, synthesize the sensor data into the mileage data of a module through weighted average.

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